XML 106 R94.htm IDEA: XBRL DOCUMENT v3.22.4

Fair Value of Assets and Liabilities - Recorded on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	$ 802,096	$ 1,167,568
SBA-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	44,355	33,478
Debentures of government sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	135,106	188,527
U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	10,269	11,630
Obligations of state and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	102,123	134,000
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	33,276	38,495
Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	1,462	1,862
Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial assets (interest rate contracts)	0
Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2) | Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial assets (interest rate contracts)	602
Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3) | Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial assets (interest rate contracts)	0
Assets and liabilities at fair value measured on a recurring basis | Corporate bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)		0
Assets and liabilities at fair value measured on a recurring basis | Corporate bonds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)		38,495
Assets and liabilities at fair value measured on a recurring basis | Corporate bonds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)		0
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial assets (interest rate contracts)	602
Derivative financial liabilities (interest rate contracts)		1,085
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	475,505	759,576
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | SBA-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	44,355	33,478
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | Debentures of government sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	135,106	188,527
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	10,269	11,630
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | Obligations of state and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	102,123	134,000
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	33,276	38,495
Carrying Value | Assets and liabilities at fair value measured on a recurring basis | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	1,462	1,862
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial liabilities (interest rate contracts)		0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2) | Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial liabilities (interest rate contracts)		1,085
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3) | Interest rate contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial liabilities (interest rate contracts)		0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	475,505	759,576
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | SBA-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | SBA-backed securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	44,355	33,478
Fair Value | Assets and liabilities at fair value measured on a recurring basis | SBA-backed securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Debentures of government sponsored agencies | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Debentures of government sponsored agencies | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	135,106	188,527
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Debentures of government sponsored agencies | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | U.S. Treasury securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	10,269	11,630
Fair Value | Assets and liabilities at fair value measured on a recurring basis | U.S. Treasury securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | U.S. Treasury securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Obligations of state and political subdivisions | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Obligations of state and political subdivisions | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	102,123	134,000
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Obligations of state and political subdivisions | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Corporate bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Corporate bonds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	33,276
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Corporate bonds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Asset-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	0	0
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Asset-backed securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	1,462	1,862
Fair Value | Assets and liabilities at fair value measured on a recurring basis | Asset-backed securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, at fair value (net of zero allowance for credit losses at December 31, 2022 and 2021)	$ 0	$ 0

X

- Definition

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

Name:	us-gaap_DerivativeAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

+ Details

Name:	us-gaap_DerivativeLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=bmrc_SmallBusinessAdministrationSBABackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: